Methods for retracting tissues to improve visualization or prevent trauma to tissues impinging on a surgical site have been used for centuries. Optical instruments, such as speculums or retraction devices require a surgical opening to be made for their insertion thereby adding to the number of wounds required to accomplish proper exposure.
Heretofore these devices have been placed through small or large incisions in order to bring retracting or hooking surface to bear against the tissue to be retracted.
For cataract surgery a large pupil of 6 mm or more is required. When pupils do not dilate well due to the presence of adhesions, inability of the iris musculature to respond to pharmacologic mydriasis, or for other reasons, a mechanical method of enlarging the pupil is necessary. Stretching the iris has been the most common methodology in the last thirty years.
Speculums were employed in the past for retracting the iris during intracapsular cataract surgery whereby removal of the entire lens utilizing an incision of 8-10 mm or larger was required. The Rosenbaum Drews iris retractor was one such example. The surgeon must hold the retractor with one hand while an assistant lifted the cornea and the surgeon removed the lens with a cryoprobe or other such lens removal device with the dominant hand. Models for left and right handed surgeons were designed. With the onset of modern small incision surgery 1.5-6 mm incisions have been employed. The size limitations of a small incision and the presence of a small pupil required that the iris be cut and moved out of the way, stretched using (Kuglen) hooks, (Beehler) pupil stretchers or that a small (peripheral) or large section of the iris be removed (sector iridectomy) to facilitate cataract removal. Recently the presence of a condition whereby the iris prolapses through the small incision has been described. This condition has been given the name “intraocular floppy iris syndrome” or IFIS. Enlarging the incision or introducing instruments into the eye requires that the pupil remain dilated and the iris be kept away from the incision. Intraocular hooks for retracting the iris or lens capsule developed by Makool are introduced through individual small incisions. Four or five of these incisions and hooks are required to adequately retract the iris. With multiple incisions and multiple hooks to retract the iris, insertion and removal may be problematic. The hooks may rotate into the iris stroma damaging the iris and causing bleeding thereby making surgery more difficult. Insertion and removal of the hooks is technically difficult and many surgeons avoid them for this reason. The introduction of pupillary rings developed by Milverton “Perfect Pupil™”, Malyugin “Malyugin ring” is another method for retracting the iris through the incision which is made for cataract removal. An expanding ring is inserted through the small cataract incision. The expense of the device, and the necessity for learning a new methodology with specially developed insertion and removal tools has limited their use.